Smoothing of On-Off Damper Force with the Variable Damping Coefficient

Abstract

Semi-active on-off damper can achieve a good performance close to that of an active control damper with much lower cost and complexity. However, the acceleration response of an on-off damper exhibits discontinuities at the time of switching, thus a significant jerk may be experienced by the system mass. In this study, based on analysis of present semi-active on-off damper, two types of new "on-off" dampers with the variable damping coefficient, which can improve significantly discontinuties at the time of switching, were developed. The time rate of change of damping force and jerk on mass(the time rate of change of acceleration)were investigated and used to evaluate the smooth degree of the damping force and the acceleration. The vibration performance was compared with that of conventional semi-active system. The result shows that the new types of on-off dampers can improved the vibration performance in the high frequency ranges.